i) Technical Field of the Invention
This invention relates to a technique of improving repeated striking performance of a piano.
ii) Description of the Related Art
A piano is conventionally provided with a known action mechanism that operates in response to key depression and makes a striking member strike a string, as disclosed in Unexamined Japanese Patent Publication No. 9-281959, for example.
Also, as can be seen in Unexamined Japanese Utility Publication No. 49-919, the action mechanism comprises a substantially L-shaped jack composed of elongated portions, specifically, a big jack portion and a small jack portion. The small jack portion is arranged almost perpendicular to the big jack portion. The thickness of the big jack portion and the small jack portion is nearly constant in the direction of key arrangement in a state of the jack being fitted in the piano.
In the action mechanism as above, the jack is raised in response to key depression and pushes up a shank roller, that is, a part of the striking member, with the apex of the big jack portion. Furthermore, when the free end of the small jack portion abuts on a regulating button, the jack is rotated and the apex of the big jack portion is separated from the shank roller. Then, the striking member, which was pushed up by the jack, swings to a string side to strike a string.